The small satellite galaxies of our Milky Way are the most ancient, most metal-poor, and most dark-matter-
dominated systems known. These extreme objects offer a unique opportunity to test the standard model of
cosmology, while also providing insights into the formation of galaxies, stars, and the heavy elements. Over the
past three years, the unprecedented sensitivity of the Dark Energy Camera has allowed us to double the known
population of ultra-faint Milky Way satellites. I will discuss recent results, outstanding questions, and upcoming
advances in the study of the Milky Way's dark companions.